1. Field of the Invention
This invention relates to methods and apparatus for folding absorbent pads of the type used with obstetrical patients under post-natal care and, more particularly, for folding the pads by thirds in order to achieve more compact packaging of the pads.
2. Description of the Prior Art
Various products have been designed for absorbing excreted body fluids, for example feminime hygiene products. One such type of product, the tampon, is clearly unsuitable for obstetrical patients. Obstetrical pads are more similar to sanitary napkins, but have been particularly designed for use with an obstetrical patient within the first few days after delivery. Obstetrical pads are substantially larger and contain more absorbent material in order to perform satisfactorily in absorbing and containing the moisture encountered in use.
Obstetrical pads, as they have been developed, commonly comprise two highly absorbent fluff pads with layers of soft cellulose tissue in between and fully enclosing them. The natural wicking action of the tissue draws the moisture from the center out to the ends of the pad. This complete, even dispersion allows the fluff pads to absorb their maximum capacity. The collected moisture is then contained within a soft polypropylene shielf to prevent soiling of clothes or linen. The outside enclosing layer, a non-woven covering of substantially tubular form, extends in both directions past the ends of the inner fluff pads and tissue layers to provide a pair of high-tensile tabs, or "tails", to provide the means by which the pad is held in proper position in use.
Until recently, obstetrical pads of this type have been folded in half and packed in individual oblong packages. This manner of folding places the contact portion of the pad inside, thus maintaining a sterile field in this region. Folding in this manner also naturally, places both of the end tabs or "tails" together at the same end of the package, thus making them readily available to the nurse or other personnel opening the package to grasp the tails and use them as handles in placing the pad in position for use. This provides a professional advantage in that the medical practitioner can easily handle the pad without contaminating the sterile field.
Recently, however, it has been discovered that substantial savings in packing space can be realized from the folding of the pads in thirds, thus developing so-called "three-fold" pads. The resulting package of a single pad is more cubical in form than the oblong packs containing the "two-fold" pads. It has been found that three-fold pads can be packaged in as much as 40% less volume than a comparable number of two-fold pads, the improvement in packing space being derived principally from the greater compressibility of the fluff layers when the pads are folded in thirds. This greater compactness of the three-fold pads results in substantial savings in processing and storage at various points along the line from the manufacturing plant to the inventory storage of the ultimate user. For example, after the pads are manufactured, folded and individually packaged, they are placed in bags of one dozen each and the bags are placed in shipping cartons. These cartons are run through a sterilizer in which the air is first evacuated and then steam at approximately 200.degree. F. is introduced to permeate through the package wrappings and sterilize the contents. Because of the substantial reduction in the volume of the individual pads, the grade of throughput in the sterilizer is substantially increased. Less warehouse space is required for the storage of a given number of pads. Because the pads are extremely light for their volume, so that the limitation on transport is volume rather than weight, a given truck or other transport vehicle can carry a substantially greater number of pads. The inventory storage capacity at the hospital or other customer is correspondingly improved, again resulting in savings derived from the increased compactness of the pads.
A further benefit is realized from the development of the three-fold pad. With two-fold pads, the single fold thereof is in the middle, the point at which a crease develops the most discomfort for the user. With the three-fold pad, the folds are displaced from the center of the pad and one of the folds, being folded about another portion of the pad, does not present a crease at all. However, in the folding of the pad in thirds, unlike the folding of a pad in half, the two end portions or tails do not naturally end up adjacent each other and particular pains must be taken in the folding of the three-fold pad in order to achieve this convenience for the user of placing the tails together for ready access when the package is opened and, more importantly, the capability of handling the pad without contaminating the sterile field. Because of the problems involved in the folding of the three-fold pads, particular methods and apparatus have been developed to achieve the desired folding as the manufactured pads come off the fabrication production line.